In the past year, we have completed planned analysis of results from the clinical protocol, Assessment of the Effects of A DPP-4-Specific Inhibitor (Sitagliptin/Januvia) on Immune Function in Healthy Individuals. Our analysis has indicated that sitagliptin does not significantly alter most of the immune readouts we measured, including levels of plasma TGF-beta and other cytokines, and flow cytometry on PBMCs. Flow cytometry data collected include Treg analysis and expression of CD26 on lymphocyte subsets. We did observe small but significant changes in CD26 expression early after sitagliptin treatment, but these changes were not sustained, and therefore are not likely to be clinically relevant. This study has been accepted for publication.